670
FXUS63 KPAH 171657
AFDPAH

Area Forecast Discussion
National Weather Service Paducah KY
1157 AM CDT Fri Jul 17 2026

.KEY MESSAGES...

- There is a 30-60% chance of daily showers and thunderstorms
  through the entire weekend. Rain chances peak during the
  afternoon hours, but the one exception is Saturday evening
  when a stronger gusty storm cannot be ruled out in the
  northeast across southwest Indiana.

- A Heat Advisory is now in effect from Saturday afternoon
  through Tuesday evening for southwest portions of the region.
  Daily high temperatures trend more into the lower 90s through
  early next week with heat index values between 100-105 degrees.

- Northerly flow may briefly cause moderate unhealthy air
  quality conditions across the far north on Sunday while the
  latter half of next week may pose a more impactful risk due to
  the ongoing Northwestern Ontario wildfire smoke.

&&

.DISCUSSION...
Issued at 1156 AM CDT Fri Jul 17 2026

Daily scattered showers and isolated thunderstorms will continue
today through the weekend as a weak shortwave trough moves across
the FA this afternoon. Rain chances around 30-60% peak during the
afternoon hours. With PWAT`s around 2.00-2.15 inches combined with
sfc mixing ratios around 19-20 g/kg, hourly rainfall rates will
be capable of exceeding 2 inches per hour that will quickly
yield typical ponding and runoff on roadways in low-lying
locations. The shear increases to 15-20 kts on Saturday with
2000-2500 J/kg of MLCAPE. Combined with a theta-e difference of
25-30K and sfc-3km lapse rates around 7.0-7.5 C/km, there
remains the potential for an isolated strong to severe storm in
the northeast mainly across southwest Indiana where SPC has a
marginal risk in their D2 outlook. As a cold front approaches
Saturday evening from the north, timing may not line up with the
best instability. The 12z HRRR shows a trailing line of storms
not clipping the FA until closer to Midnight, separate from
widely scattered pulse storms during peak heating.

The aformentioned cold front briefly stalls in the vicinity of I-64
on Sunday before lifting back north. There is the potential for
brief moderate unhealthy air quality conditions north of the
front, but PM2.5 values of 50-60 ug/m3 typically are still
acceptable for most groups. The bigger concern however will be
the hot and humid conditions. After collaborating with WFO LSX,
have issued a Heat Advisory from Saturday afternoon through
Tuesday evening for all of southeast Missouri, and portions of
southern Illinois and far western Kentucky. 4 consecutive days
of heat index values between 100-105 degrees are expected;
however, there is the potential for values to near 110 degrees
across the entire region on Tuesday. While another cold front
approaches by Tuesday evening, the front may pose another risk
for a few isolated strong to severe storms with modest
improvement in both wind shear and forcing.

Temperatures trend about 5 degrees below normal on Wednesday into
the latter half of next week behind the front. Highs by the NBM are
progged to reach only the low to mid 80s. However, northerly flow
associated with upper-level troughing over the Ohio Valley may yield
a greater risk for poor air quality conditions due to the ongoing
wildfires in Canada, and will be something to monitor more in the
coming days.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1156 AM CDT Fri Jul 17 2026

Scattered showers and isolated thunderstorms will continue to
increase in coverage this afternoon across the region, with
KEVV/KOWB experiencing the greatest coverage. Heavy downpours can
briefly cause IFR or lower vsby reductions, while MVFR
conditions will be more prevailing when storms are in the
vicinity. Winds tonight turn light & variable, but increase to
6-8 kts out of the west Saturday morning.

&&

.PAH WATCHES/WARNINGS/ADVISORIES...
IL...Heat Advisory from noon Saturday to 7 PM CDT Tuesday for
     ILZ080-081-084>086-088>090-092>094.
MO...Heat Advisory from noon Saturday to 7 PM CDT Tuesday for
     MOZ076-086-087-100-107>112-114.
IN...None.
KY...Heat Advisory from noon Saturday to 7 PM CDT Tuesday for
     KYZ001>009.

&&

$$

DISCUSSION...DW
AVIATION...DW